On the one hand, though you should obviously bring that up to the doctor and etc because there could be other issues, purely as a matter of "how much should you worry" I'd say not very. Surgery often disrupts nerves and as long as it's not a huge area (2x3 isn't huge given the extent of the surgery) and as long as it doesn't get bigger (you might want to mark its borders with permanent marker, if possible), you're probably ok. And there's even a chance you'll eventually regain feeling, though it could take a while. Due to a late-caught problem involving handcuffs and enthusiasm, my ex girl lost feeling in her hand in the meaty area beneath the thumb but about a year later sensation has fully returned as the body reconnects nerves and etc.

Seriously, basketball though? Jeez.

Anyhow, more humanly, hope you finally got some pain-killers and that other than that and the shower-issues your recovery is going more or less smoothly.